Classification systems of Charcot arthropathy

There are several classification systems used to classify Charcot arthropathy. The Eichenholtz classification of Charcot arthropathy is one such classification and uses a temporal-based approach ¹. Another classification system is the Brodsky classification which uses an anatomical approach ¹. Both classification systems have significantly changed the approach and management of Charcot arthropathy ².

Usage

The Eichenholtz classification uses a temporal-based approach and divides Charcot foot into different stages, according to radiographic and clinical criteria, with an additional treatment recommendation ¹. It distinguishes the pathophysiology in terms of radiographic and clinical findings⁴. 

Brodsky's classification, on the other hand, relies heavily on the anatomical distribution of the deformity. Although many anatomical classifications of Charcot were devised, Brodsky's classification remains one of the widely used classification systems¹. Because both have limitations on their own, Eichenholtz and modified Brodsky's classification are used concurrently to facilitate Charcot arthropathy management¹.

Eichenholtz classification

Stage 0 (prodromal)

It usually occurs with an acute sprain of the ankle or foot in the background of diabetic neuropathy ⁵.

• clinical findings: joint oedema, erythema and warm-to-touch

• negative radiographic evidence (except MRI)

Treatment includes patient education on protective footwear and diabetic management. Regular monitoring with serial radiographs is also recommended to prevent progressive bone destruction¹.

Stage 1 (fragmentation)

Stage 1 progresses as there is bony destruction resulting in ligamentous laxity and subluxation ¹.

• clinical findings: joint oedema, erythema and joint instability

• radiographic evidence: bone destruction, debris formation and/or dislocation

Clinicians suggest protective weight-bearing, ideally with total contact casting or pneumatic brace until complete resolution of stage 1, which could take up to 4 months ¹.

Stage 2 (coalescence)

New bone formation begins in this stage and there are reduced clinical findings. Periarticular debris is absorbed and larger bone fragments form calluses ¹.

• clinical findings: decreased joint oedema and erythema

• radiographic evidence: absorption of debris, sclerosis formation

To facilitate bone healing, protective weight-bearing is continued and in some cases, Charcot restraint orthotic walker or clamshell ankle-foot orthosis is used ¹.

Stage 3 (reconstruction)

The joint structure becomes more stable even with deformity present. Bone formation is more evident ¹.

• clinical findings: resolved joint oedema, stable joint with fixed deformity

• radiographic evidence: consolidation and remodelling of fracture fragments

For non-severe cases, conservative management is still recommended with custom inlay shoes for plantigrade feet. For non-plantigrade feet, a more aggressive approach is sought. If conservative methods fail, exostectomy is done to debride the bony prominence. Exostectomy is found to have a higher limb salvage rate (around 90%) ⁶.

Arthrodesis with internal fixation is recommended as a last resort before amputation of the foot for severe fixed deformity of the foot and ankle with recurrent ulcerations despite conservative therapy ⁶. However, there is a high incidence of incomplete bone union ⁶.

Brodsky Classification

Type 1

• location: midfoot

• joints involved: tarsometatarsal, naviculocuneiform

Type 2

• location: hindfoot

• joints involved: subtalar, talonavicular, calcanecuboid

Type 3

• 3A

  • location: ankle

  • joints involved: tibiotalar

• 3B

  • location: calcaneus

  • tuberosity fracture

Type 4

• location: multiple joints

• joints involved: sequential, concurrent

Type 5

• location: forefoot

• joints involved: metatarsophalangeal

History and etymology

The American orthopaedic surgeon Sidney N. Eichenholtz identified clinical, radiographic and pathologic differences in Charcot arthropathy and published the classification in 1966, which consisted of three stages initially. The "prodromal" stage was added later by the Japanese T Shibata and colleagues ⁴.

The American orthopaedic surgeon James W Brodsky adopted his classification after noticing limitations in Eichenholtz's stages ¹. This classification system was also later modified and extended by the Canadian orthopaedic surgeon Elly Trepman and colleagues to include fourth and fifth types ⁴.